I've just received a Bluetooth Serial Port Wireless Module, which I'm going to use to control my robot. It's a pretty cheap $8 module from DX, nevertheless, instantly working without any problems. So I've made a quick setup involving a Putty Terminal allowing me to send simple commands from my PC directly to the Arduino board through an established wireless serial line. The ultimate plan is to send individual keystrokes and let the robot translate them into actions like: walking, turning, etc. The prototype works perfectly: